This application is a 371 of PCT/FR00/00837 Apr. 4, 2000.
The invention relates to compounds selectively inhibiting the Txcex39xcex42 lymphocytes carriers of receivers at variable regions Vxcex39 and Vxcex42.
The Txcex3xcex4 lymphocytes of primates present in the peripheral blood (humans, monkeys) represent, in the healthy individual, conventionally 1 to 5% of the lymphocytes of the blood and play a role in the immune system. It has been shown that they recognize their antigenic ligands by direct interaction with the antigen, without presentation by molecules of CMH of a presenting cell. The Txcex39xcex42 lymphocytes (sometimes also called Txcex32xcex42 lymphocytes) are the Txcex3xcex4 lymphocytes carrying TCR receivers at variable regions Vxcex39 and Vxcex42. They represent the majority of the Txcex3xcex4 lymphocytes of human blood.
When they are activated, the Txcex3xcex4 lymphocytes exert a strong cytotoxic activity unrestrained by CMH, particularly effective to kill various types of cells, particularly pathogenic cells. Nevertheless, the massive activation of the Txcex3xcex4 lymphocytes accompanying sometimes the development of certain pathologies, can have or lead to a pathogenic character. Such is the case in particular for the auto-immune maladies such as plaque sclerosis (Wucherpfennig K. et al xe2x80x9cxcex3xcex4T cell receptor repertoire in acute multiple scerosis lesionxe2x80x9d 1992, PNAS 89, 4588) or the Behxc3xa7et malady (Yamashita N. et al xe2x80x9cRole of xcex3xcex4T lymphocytes in the development of Behxc3xa7et diseasexe2x80x9d Clinical Experimental, Immunology, 107(2), 241-247).
Such is the case moreover for a certain number of bacterial pathologies such as brucellosis, tularemia, salmonelloses, tuberculosis, ehrlichiosis, or parasitic pathologies such as malaria (malarial attack), visceral leishmaniosis, toxoplasmosis (for example Morita C. T. et al, xe2x80x9cDirect presentation of non peptide prenyl pyrophosphate antigens to human gamma delta T cellsxe2x80x9d, 1996, Research in Immunology, Vol. 147, p 347-353).
Various antigens of Txcex39xcex42 lymphocytes have been described (WO-9520673, U.S. Pat. No. 5,639,653, xe2x80x9cNatural and synthetic non peptide antigens recognized by human xcex3xcex4T cellsxe2x80x9d, Yoshimasa Tanaka et al, Nature, 375, 1995, pp 155-158). Nevertheless, these natural antigens are not completely identified. Moreover, it is known that the mechanism of activation of the Txcex39xcex42 lymphocytes by these antigens is particular, because it does not imply any known molecule of CMH (major complex of histocompatibility). But the nature of this mechanism remains unexplained, such that the problem of adjusting inhibitors of Txcex39xcex42 lymphocytes remains unsolved.
WO-95/20673 also indicates that the principals having a phosphatase enzymatic activity (phosphohydrolase phosphoric monoester and/or pyrophosphatase nucleotide and/or phosphohydrolase phosphoric diester) such as the alkaline phosphatase, are adapted to inhibit the antigenic activity of natural origin, the so-called TUBag, from a mycobacterial extract, vis-à-vis Txcex39xcex42 lymphocytes. Nevertheless, this inhibition takes place by cleaving the antigens and thus does not act on the Txcex39xcex42 lymphocytes themselves. Moreover, it is not specific and poses problems of uncontrollable secondary effects to the extent that the biological or physiological media themselves include numerous phosphorylated compounds and natural phosphatase enzymatic activities.
The invention thus seeks to provide compounds for selective inhibition of the Txcex39xcex42 lymphocytic stimulation, which is to say specific immunosuppressive compounds for Txcex39xcex42 lymphocytes.
The invention seeks more particularly to provide such compounds which will be compatible, on the one hand, with administration to a primate and, on the other hand, with considerations of profitability for industrial use (which must be produced in a simple manner, in large quantities, at an acceptable cost on an industrial scale).
Moreover, it is also desirable that the inhibition of the Txcex39xcex42 lymphocytes for the treatment of an excess of activation of the Txcex39xcex42 lymphocytes does not destroy definitively the immune system of the patient or of the lymphocytic biological medium. Thus, the invention also seeks to provide compounds having an inhibitory activity which will be not only selective with respect to Txcex39xcex42 lymphocytes, but also reversible, such that the activity of the Txcex39xcex42 lymphocytes may ultimately be restored.
The invention also seeks to provide new phosphorated compounds and their process for production.
The invention also seeks to provide applications of the compounds according to the invention for the selective and reversible inhibition of the Txcex39xcex42 lymphocytes. More particularly, the invention seeks to provide applications for the compounds according to the invention for therapeutic use, of the applications of the compounds according to the invention for diagnosis, and applications of the compounds according to the invention for the experimental study of Txcex39xcex42 lymphocytes, their antigens or specific immunosuppressive agents.
The invention seeks particularly to provide a treatment for pathologies implying an activation of the Txcex39xcex42 lymphocytes, and particularly selected from malaria (malarial attack), visceral leishmaniosis, toxoplasmosis, brucellosis, tularemia, salmonelloses, tuberculosis, ehrlichiosis, auto-immune maladies such as sclerosis by plaques or the Behxc3xa7et malady.
To do this, the invention relates to new compounds of the formula:
CH3xe2x80x94R1xe2x80x94(CH2)2xe2x80x94R2xe2x80x83xe2x80x83(I)
in which R1 is selected from the following functions: 
and R2 is selected from the following groups:
in which CAT+ represents one or more organic or mineral cations (including the proton) identical or different, in the same compound, except for 3-methyl-3-butene-1-yl-difluoromethylenediphosphonate, and 3-methyl-3-butene-1-yl-methylenediphosphonate.
The compounds according to formula (I) of the invention are the following (IUPAC nomenclature):
R1: tertiary alcohol function:
3-methyl-3-butanol-1-yl-methylenediphosphonate;
3-methyl-3-butanol-1-yl-monofluoromethylenediphosphonate;
3-methyl-3-butanol-1-yl-difluoromethylenediphosphonate;
R1: 1,2 diol function:
3-methyl-3,4-butanediol-1-yl-methylenediphosphonate;
3-methyl-3,4-butanediol-1-yl-monofluoromethylenediphosphonate;
3-methyl-3,4-butanediol-1-yl-difluoromethylenediphosphonate.
R1: halohydrin function wherein X=Cl, Br, I:
3-(chloromethyl)-3-butanol-1-yl-methylenediphosphonate;
3-(chloromethyl)-3-butanol-1-yl-monofluoromethylenediphosphonate;
3-(chloromethyl)-3-butanol-1-yl-difluoromethylenediphosphonate;
3-(bromomethyl)-3-butanol-1-yl-methylenediphosphonate;
3-(bromomethyl)-3-butanol-1-yl-monofluoromethylenediphosphonate;
3-(bromomethyl)-3-butanol-1-yl-difluoromethylenediphosphonate;
3-(iodomethyl)-3-butanol-1-yl-monofluoromethylenediphosphonate;
3-(iodomethyl)-3-butanol-1-yl-methylenediphosphonate;
3-(iodomethyl)-3-butanol-1-yl-difluoromethylenediphosphonate.
R1: epoxyd function:
3,4-epoxy-3-methyl-1-butyl-methylenediphosphonate;
3,4-epoxy-3-methyl-1-butyl-monofluoromethylenediphosphonate;
3,4-epoxy-3-methyl-1-butyl-difluoromethylenediphosphonate.
R1: alkene function:
3-methyl-3-butene-1-yl-methylenediphosphonate;
3-methyl-3-butene-1-yl-monofluoromethylenediphosphonate;
3-methyl-3-butene-1-yl-difluoromethylenediphosphonate.
R1: aldehyde function (R3=H):
3-formyl-1-butyl-methylenediphosphonate;
3-formyl-1-butyl-monofluoromethylenediphosphonate;
3-formyl-1-butyl-difluoromethylenediphosphonate.
R1: xcex1-hydroxyaldehyde (R3=OH):
3-formyl-3-butanol-1-yl-methylenediphosphonate;
3-formyl-3-butanol-1-yl-monofluoromethylenediphosphonate;
3-formyl-3-butanol-1-yl-difluoromethylenediphosphonate.
The 3-methyl-3-butene-1-yl-difluoromethylenediphosphonate has been described by xe2x80x9cphosphorylation of isoprenoid alcoholsxe2x80x9d V. Jo Davisson et al., J. Org. Chem. 1986, 51, 4775.
The invention moreover relates to compounds of formula (I) above (including 3-methyl-3-butene-1-yl-difluoromethylenediphosphonate) as to their uses as agents for the selective inhibition of Txcex39xcex42 lymphocytes.
The invention relates more particularly to the compounds of formula (I) above, as to their uses as agents for the inhibition of selective phosphoantigenic activation of Txcex39xcex42 lymphocytes by a phosphated antigen (phosphoantigen), such as a natural antigen (for example the Tubag disclosed by WO 95/20673), or artificial antigens such as IPP (3-methyl-3-butene-1-yl-pyrophosphate), a phosphohalohydrin compound such as BrHPP (3-(bromomethyl)-3-butanol-1-yl-diphosphate) or IHPP (3-(iodomethyl)-3-butanol-1-yl-diphosphate), or a phosphoepoxid compound such as EpoxPP (3,4 epoxy-3-methyl-1-butyl-diphosphate).
Although the real mechanism for the inhibition of Txcex39xcex42 lymphocytes by the compounds of the invention is not definitely set forth, the work of the inventors permits believing that such a selective inhibition of the Txcex39xcex42 lymphocytes can be obtained by compounds which satisfy the three following conditions:
1) having a molecule of topologic form corresponding to formula (I),
2) having an R1 function adapted to form a covalent bond by a reaction of the nucleophile substitution or addition type, or the electrophile addition in the presence of Txcex39xcex42 lymphocytes,
3) having a group structurally analogous to a pyrophosphate, but adapted to inhibit the enzymatic hydrolysis of the terminal phosphate necessary to the activation of Txcex39xcex42 lymphocytes.
Such a compound can thus have the property of occupying the antigenic recognition sites of the Vxcex39 Vxcex42 receptors thanks to conditions 1) and 2), but preventing the transduction of the activation signal to the lymphocyte because the enzymatic hydrolysis of the terminal phosphate, which the inventors think would be necessary for this transduction, is inhibited.
The function R1 is selected so as to be compatible with conditions 1) and 2) above and to permit obtaining the compound according to the invention. The CH3xe2x80x94R1xe2x80x94(CH2)2xe2x80x94 group must thus be an antigenic ligand of the T Vxcex39 Vxcex42 receptor. It can be isopentenyl, of course, which is an antigenic ligand. The inventors have shown moreover that the other groups CH3xe2x80x94R1xe2x80x94(CH2))2xe2x80x94 of the formula (I) mentioned above also permit obtaining inhibitors of the Txcex39xcex42 lymphocytes.
The group R2 is selected from structural analogs of pyrophosphates that are unhydrolizable or weakly hydrolizable. Such analogs of the pyrophosphates are known per se (cf. xe2x80x9cATP analogsxe2x80x9d by R. G. Yount (1975) Adv. Enzymol. Vol. 43, p 1-56; xe2x80x9cSynthesis of monofluoro- and difluoro-methylenephosphonate analogues of sn-glycerol-3-phosphate as substrates for glycerol-3-phosphate dehydrogenase and the X-Ray structure of the fluoromethylenephosphonate moietyxe2x80x9d by J. Nieschalk et al. (1996) Tetrahedon vol. 52 p165-176; xe2x80x9cThe difluoromethylenephosphate moiety as a phosphate mimic: X ray structure of 2 amino-1,1-difluoro ethylphosphonic acidxe2x80x9d by R. D. Chambers et al. (1990) J. Chem. Soc. Chem. Commun. vol. 15, p 1053-1054).
A group R2 should also be selected to be compatible with the synthesis of the compound according to the invention.
The invention also relates to uses of the compounds according to the invention as inhibitors for the Txcex39xcex42 lymphocytes of primates, particularly as inhibitors of the proliferation and/or the cytotoxic activity and/or the production of mediatory substances by the Txcex39xcex42 lymphocytes of the primates with TCR receptors comprising the variable regions Vxcex39 and Vxcex42.
The invention also relates to applications of the compounds according to the invention for the treatment of cells sensitive to Txcex39xcex42 lymphocytes of primates, in a natural or artificial medium adapted to contain Txcex39xcex42 lymphocytes, in which said cells can be placed into contact with these Txcex39xcex42 lymphocytes, this medium being compatible with the compounds according to the invention (which is to say it is not susceptible to cause degradation at least under certain conditions of treatment).
By xe2x80x9ccell sensitive to Txcex39xcex42 lymphocytesxe2x80x9d is meant any cell subject to the effective activity induced by Txcex39xcex42 lymphocytes (cellular death, the invention permitting preventing destruction of the cells by lymphocytes); reception of salting out by the Txcex39xcex42 lymphocytes (TNF-xcex1, INF-xcex3 . . . ); cellular proliferation induced by Txcex39xcex42 lymphocytes.
The invention thus extends to a process for the selective inhibition of the Txcex39xcex42 lymphocytes, particularly to a process for selective inhibition of the proliferation of Txcex39xcex42 lymphocytes and/or of the cytotoxic activity of the Txcex39xcex42 lymphocytes and/or the production of mediatory substances by the Txcex39xcex42 lymphocytes, in which these Txcex39xcex42 lymphocytes are placed in contact with at least one compound according to the invention in a medium containing Txcex39xcex42 lymphocytes.
Preferably, and according to the invention, there is used at least one compound according to the invention at a concentration in the medium which gives rise to a selective inhibition of the polyclonal proliferation of the Txcex39xcex42 lymphocytes. This medium can be selected from human blood, the blood of a non-human primate, extracts of human blood, and extracts of the blood of a non-human primate.
Preferably, and according to the invention, there is used a concentration greater than the IC50 concentration of the compound according to the invention, defined as that permitting reducing by 50% the intensity of the response of the Txcex39xcex42 lymphocytes, according to the induced cytotoxicity test, with a standard antigenic stimulant, particularly BrHPP at 80 nM.
Said medium can be extracorporeal, said inhibition process according to the invention being then an extracorporeal treatment, which can particularly take place in the laboratory, for example by the diagnosis or the study of the Txcex39xcex42 lymphocytes or of their properties. For diagnosis, the inhibition of the Txcex39xcex42 lymphocytes can serve to evaluate the condition of activation of the Txcex39xcex42 lymphocytes removed from a patient, according to their behavior after placing them in contact with an inhibitory quantity of a compound according to the invention.
Said medium can also be intracorporeal, the selective inhibition of the Txcex39xcex42 lymphocytes being then a therapeutic or diagnostic utility.
More particularly, said medium is the peripheral blood of a primate. The invention thus includes in particular a process for the selective inhibition of Txcex39xcex42 lymphocytes of the peripheral blood of a primatexe2x80x94particularly humanxe2x80x94in which there is administered a quantity adapted to inhibit the Txcex39xcex42 lymphocytes, of at least one compound according to the invention. There is thus administered at least one compound according to the invention by any routexe2x80x94notably parenteral in the peripheral bloodxe2x80x94.
Said medium can also be a cellular site to be treated, and there is administered at least one compound according to the invention directly in contact with the cellular site to be treated (topical administration).
Thus, the invention includes applications of the compounds according to the invention therapeutically for the curative or preventive treatment of pathologies involving an activation of the Txcex39xcex42 lymphocytes of primates in a medium that can contain Txcex39xcex42 lymphocytes.
The invention thus also relates to the compounds of the formula (I) for their use as active therapeutic substances in primates. The invention also relates to the use of the compounds according to formula (I), for their use in a therapeutic composition adapted to be administered to a primate for the preventive or curative treatment of a pathology involving the activation of Txcex39xcex42 lymphocytes.
The invention relates in particular to therapeutic uses of the compounds according to the invention for the treatment of pathologies of primates belonging to the group formed by parasitoses selected from malaria (paludism), visceral leishmaniosis and toxoplasmosis; auto-immune maladiesxe2x80x94particularly plaque scleroses and the Behxc3xa7et maladyxe2x80x94involving an activation of the Txcex39xcex42 lymphocytes; bacterial pathologies selected from brucellosis, tularemia, salmonelloses, tuberculosis, and ehrlichiosis. According to the invention, there is administered a therapeutic composition adapted to release, in the peripheral blood and/or at a cellular site to be treated, a quantity of at least one compound according to the invention adapted to inhibit the Txcex39xcex42 lymphocytes.
Thus, it has been shown generally in the prior art mentioned above, that a composition having the property of inhibiting Txcex39xcex42 lymphocytes can be preferably used for the treatment of these pathologies.
Conventionally, in all the texts, the terms xe2x80x9ctherapyxe2x80x9d or xe2x80x9ctherapeuticxe2x80x9d include not only the curative treatments or care, but also the preventive treatments (prophylaxis) such as vaccination. Thus, by permitting selective inhibition of the Txcex39xcex42 lymphocytes, the invention permits immunostimulation treatments that can preferably also serve as prophylaxis by preventing the development of Txcex39xcex42 lymphocytes, as well as curing by inhibiting Txcex39xcex42 lymphocytes.
The invention thus also relates to a therapeutic or diagnostic composition comprising at least one compound according to the invention. More particularly, the invention relates to a therapeutic compound comprising a quantity suitable to be administered to a primatexe2x80x94particularly in contact with the peripheral blood or by topical routexe2x80x94of at least one compound according to the inventionxe2x80x94particularly for the preventive or curative treatment of the above-mentioned pathologies. A composition according to the invention can be an immunostimulatory composition, or a vaccine, the compounds according to the invention being antigens selectively inhibiting the Txcex39xcex42 lymphocytes.
A therapeutic composition according to the invention can be prepared in galenic form adapted to be administered by any route, particularly by the parenteral route directly into the peripheral blood of the primate, with at least one compound according to the invention in a quantity adapted to inhibit the Txcex39xcex42 lymphocytes and one or several suitable excipients. Given the active concentration of the compounds according to the invention (of the order of 10 to 1000 xcexcM), such an administration is to be envisaged without the risk of toxicity.
A therapeutic composition according to the invention can also be prepared in a suitable galenic form for its topical administration, directly in contact with the Txcex39xcex42 lymphocytes.
The galenic form of a therapeutic composition according to the invention is prepared according to the selected route of administration, by conventional techniques for galenic formulation. The quantity and the concentration of the compound or compounds according to the invention, and the posology, are determined by reference to the known chemotherapeutic treatments of the maladies to be treated, given the bioactivity of the compounds according to the invention relative to the Txcex39xcex42 lymphocytes, of the individual to be treated, and of the malady in question, and of the different biological effects.
Preferably, and according to the invention, there is administered the compound according to the invention in a quantity adapted to create in the peripheral blood of the patient a concentration greater than the IC50 concentration of the compound according to the invention as defined above.
Preferably, and according to the invention, for a bioactive compound at a concentration comprised between 1 xcexcM and 1000 xcexcM, there is administered by any route a quantity of a compound or compounds according to the invention comprised between 0.1 mg and 1 gxe2x80x94particularly between 1 mg and 100 mgxe2x80x94per kilogram of weight of the patient.
Moreover, it has been shown in vitro that the compounds according to the invention have no general toxicity. Moreover, it is known that the biochemical category of molecules to which the compounds according to the invention belong (phosphoesters) constitute a family of compounds compatible with analogous and physiological biological media. The compounds according to the invention have thus no other toxic effects than those induced by their bioactivity on the Txcex39xcex42 lymphocytes.
Moreover, the compounds according to the invention have a sufficiently low molecular weight (particularly below 500) to be compatible with their elimination by renal or urinary route.
An example of formulation of an injectable therapeutic composition according to the invention for a primate of 1 kg is the following:
5 mg of sodium salt of 3,4-epoxy-3-methyl-1-butyl-methylenediphosphonate (Epox-PCP) diluted in 5 ml of sterile Ringer-Lactate buffer.
There is thus administered over 4 days: 1 dose per day of 5 mg for 1 kg of animal, corresponding to a concentration in the circulating blood of 50 mg/l, which can be greater than the IC50 concentration of 15 xcexcM for Epox-PCP (a concentration of 50 mg/l corresponding to about 160 xcexcM).
It is to be noted that most of the excipients or other conventional acceptable pharmaceutical additives used, are chemically compatible with the compounds according to the invention.
A therapeutic composition according to the invention can also preferably comprise one or several other active principles, particularly to provide a synergetic effect. In particular, a compound according to the invention can serve as a vaccine adjuvant. The vaccine therapeutic composition according to the invention is thus comprised by a known vaccine composition to which is added a quantity of compound according to the invention adapted to inhibit the Txcex39xcex42 lymphocytes which will not be able to exert their direct effective activity (for example cytotoxic), nor regulatory of the Th-1 type (for example salting out interferon and tumoral necrosis factor (TNF or xe2x80x9ctumor necrosis factorxe2x80x9d)), and thereby promoting the lymphocyte B responses (for example production of antibodies).
The invention also extends to the use of at least one compound according to the invention for the production of a therapeutic composition according to the invention. More particularly, the invention bears on the use of at least one compound according to the invention for the production of a therapeutic composition adapted for the preventive or curative treatment of a pathology involving an activation of the Txcex39xcex42 lymphocytes of primatesxe2x80x94particularly a pathology selected from the group mentioned abovexe2x80x94. In this instance, the invention also extends to the use of at least one compound according to the invention for the production of a therapeutic composition adapted to be administeredxe2x80x94particularly in contact with the peripheral blood or by topical routexe2x80x94to a primatexe2x80x94notably humanxe2x80x94for the preventive or curative treatment of a pathology as mentioned above.
The invention also relates to a process for the production of a compositionxe2x80x94particularly a therapeutic compositionxe2x80x94according to the invention, having the property of selectively inhibiting Txcex39xcex42 lymphocytes, in which there is used at least one compound according to the invention. The invention also relates to a process for the production of a therapeutic composition adapted for the preventive or curative treatment of a pathology as mentioned above, in which there is used at least one compound according to the invention. The invention bears in particular on a process for production of a therapeutic composition adapted to be administeredxe2x80x94particularly in contact with the peripheral blood or by topical route, to a primate for the preventive or curative treatment of a pathology such as mentioned above, in which there is used at least one compound according to the invention.
The compounds according to the invention can be prepared according to the reactions given hereafter, according to the different R1 and R2g groups.
In the reaction diagrams, PCP identifies the methylenediphosphonate group, PCHFP identifies the monofluoromethylenediphosphonate group, and PCF2P identifies the difluoromethylenediphosphonate group.
For R1: tertiary alcohol function, alkene, epoxyd, and R2: PCP, PCHFP, PCF2P: 
in which Ts is tosyl, TsClis tosyl chloride, 4-DMAP is 4-dimethylaminopyridine.
The tetrabutylammonium salts of the reagent R2xe2x80x94H, used in a quantity at least equal to 2 molar equivalents, are, according to the group R2 of the compound to be prepared:
for PCP: the tris(tetra-n-butylammonium) hydrogeno-methylene-diphosphonate prepared from methylene disphosphonic acid,
for PCF2P: the tris(tetra-n-butylammonium) hydrogeno-difluoromethylene-diphosphonate prepared from tetrakis(trimethylsilyl)-difluoromethylenedisphosphonate according to the procedure described by V. Jo DAVISSON et al. J. Org. Chem, 51, p 4768-4779, (1986),
for PCHFP: the tris(tetra-n-butylammonium) hydrogeno-monofluoromethylenediphosphonate prepared from tetrakis(trimethylsilyl)-monofluoromethylenediphosphonate according to the procedure described by J. NIESCHALK et al. (1996) Tetrahedron vol. 52 p165-176 and adapted according to V. Jo DAVISSON et al. J. Org. Chem., 51, p 4768-4779, (1986).
The alcohols (1) are commercially available products except the alcohol corresponding to the R1 epoxyd function which can be obtained easily (G. M. RUBOTTOM et al., Org. Synth. Coll. Vol 7, p 282 (1990), Wiley) by epoxydation of the alkene function as follows: 
(1) wherein R1: alkene function (1) wherein R1: epoxyd function
For R1: Halohydrine function (X=Cl, Br, I), and R2: PCP, PCHFP, PCF2P: 
(3) wherein R1: alkene function
Variant for R1: epoxyd function, and R2: PCP, PCHFP, PCF2P: 
For R1: 1,2-diol function, and R2: PCP, PCHFP, PCF2P: 
(3) wherein R1: alkene function
in which KmnO4 is potassium permanganate (in a quantity less than or equal to 1 molar equivalent)
For R1: aldehyde function, and R2: PCP, PCHFP, PCF2P: 
in which R2xe2x80x94H is used in a quantity at least equal to 2 molar equivalents. 
The compound (9) can be easily obtained in the form of an alcohol by the Grignard reaction between an alkenyl organomagnesium and formaldehyde or ethylene oxide, for example starting from 1-chloro-2-methyl-3-butene.
For R1: xcex1-hydroxyaldehyde function, and R2: PCP, PCHFP, PCF2P: 
in which PVPCC is Poly[vinyl(pyridinium chlorochromate)], as indicated by FRECHET J. M., WARNOCK J., and FARRALL J., J Org. Chem, vol 43, No. 13, p2618-21 (1978).